Hemorrhagic transformation in patients with large-artery atherosclerotic stroke is associated with the gut microbiota and lipopolysaccharide

Hemorrhagic transformation is a major complication of large-artery atheroscle rotic stroke(a major ischemic stro ke subtype)that wo rsens outcomes and increases mortality.Disruption of the gut microbiota is an important feature of stroke,and some specific bacteria and bacterial metabolites may contribute to hemorrhagic transformation pathogenesis.We aimed to investigate the relationship between the gut microbiota and hemorrhagic transformation in largearte ry atheroscle rotic stro ke.An observational retrospective study was conducted.From May 2020 to September 2021,blood and fecal samples were obtained upon admission from 32 patients with first-ever acute ischemic stroke and not undergoing intravenous thrombolysis or endovascular thrombectomy,as well as 16 healthy controls.Patients with stro ke who developed hemorrhagic transfo rmation(n=15)were compared to those who did not develop hemorrhagic transformation(n=17)and with healthy controls.The gut microbiota was assessed through 16S ribosomal ribonucleic acid sequencing.We also examined key components of the lipopolysaccharide pathway:lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.We observed that bacterial diversity was decreased in both the hemorrhagic transformation and non-hemorrhagic transfo rmation group compared with the healthy controls.The patients with ischemic stro ke who developed hemorrhagic transfo rmation exhibited altered gut micro biota composition,in particular an increase in the relative abundance and dive rsity of members belonging to the Enterobacteriaceae family.Plasma lipopolysaccharide and lipopolysaccharide-binding protein levels were higher in the hemorrhagic transformation group compared with the non-hemorrhagic transfo rmation group.lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14 concentrations were associated with increased abundance of Enterobacte riaceae.Next,the role of the gut microbiota in hemorrhagic transformation was evaluated using an experimental stroke rat model.In this model,transplantation of the gut microbiota from hemorrhagic transformation rats into the recipient rats triggered higher plasma levels of lipopolysaccharide,lipopolysaccharide-binding protein,and soluble CD14.Ta ken togethe r,our findings demonstrate a noticeable change in the gut microbiota and lipopolysaccharide-related inflammatory response in stroke patients with hemorrhagic transformation.This suggests that maintaining a balanced gut microbiota may be an important factor in preventing hemorrhagic transfo rmation after stro ke.

Quercetin Alleviates Lipopolysaccharide-Induced Cardiac Inflammation via Inhibiting Autophagy and Programmed Cell Death

Objective The aim of this study is to explore the potential modulatory role of quercetin against Endotoxin or lipopolysaccharide(LPS)induced septic cardiac dysfunction.Methods Specific pathogen-free chicken embryos(n=120)were allocated untreated control,phosphate buffer solution(PBS)vehicle,PBS with ethanol vehicle,LPS(500 ng/egg),LPS with quercetin treatment(10,20,or 40 nmol/egg,respectively),Quercetin groups(10,20,or 40 nmol/egg).Fifteenday-old embryonated eggs were inoculated with abovementioned solutions via the allantoic cavity.At embryonic day 19,the hearts of the embryos were collected for histopathological examination,RNA extraction,real-time polymerase chain reaction,immunohistochemical investigations,and Western blotting.Results They demonstrated that the heart presented inflammatory responses after LPS induction.The LPS-induced higher mRNA expressions of inflammation-related factors(TLR4,TNFα,MYD88,NF-κB1,IFNγ,IL-1β,IL-8,IL-6,IL-10,p38,MMP3,and MMP9)were blocked by quercetin with three dosages.Quercetin significantly decreased immunopositivity to TLR4 and MMP9 in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of TLR4,IFNγ,MMP3,and MMP9 when compared with the LPS group.Quercetin treatment prevented LPS-induced increase in the mRNA expression of Claudin 1 and ZO-1,and significantly decreased protein expression of claudin 1 when compared with the LPS group.Quercetin significantly downregulated autophagyrelated gene expressions(PPARα,SGLT1,APOA4,AMPKα1,AMPKα2,ATG5,ATG7,Beclin-1,and LC3B)and programmed cell death(Fas,Bcl-2,CASP1,CASP12,CASP3,and RIPK1)after LPS induction.Quercetin significantly decreased immunopositivity to APOA4,AMPKα2,and LC3-II/LC3-I in the treatment group when compared with the LPS group.Quercetin significantly decreased protein expressions of AMPKα1,LC3-I,and LC3-II.Quercetin significantly decreased the protein expression to CASP1 and CASP3 by immunohistochemical investigation or Western blotting in treatment group when compared with LPS group.Conclusion Quercetin alleviates cardiac inflammation induced by LPS through modulating autophagy,programmed cell death,and myocardiocytes permeability.

Natural Products Improve Organ Microcirculation Dysfunction Following Ischemia/Reperfusion-and Lipopolysaccharide-Induced Disturbances:Mechanistic and Therapeutic Views

Microcirculatory disturbances are complex processes caused by many factors,including abnormal vasomotor responses,decreased blood flow velocity,vascular endothelial cell injury,altered leukocyte and endothelial cell interactions,plasma albumin leakage,microvascular hemorrhage,and thrombosis.These disturbances involve multiple mechanisms and interactions among mechanisms that can include energy metabolism,the mitochondrial respiratory chain,oxidative stress,inflammatory factors,adhesion molecules,the cytoskeleton,vascular endothelial cells,caveolae,cell junctions,the vascular basement membrane,neutrophils,monocytes,and platelets.In clinical practice,aside from drugs that target abnormal vasomotor responses and platelet adhesion,there continues to be a lack of multi-target drugs that can regulate the complex mechanistic links and interactions underlying microcirculatory disturbances.Natural products have demonstrated obvious positive therapeutic effects in treating ischemia/reperfusion(I/R)-and lipopolysaccharide(LPS)-induced microcirculatory disturbances.In recent years,numerous research papers on the improvement of microcirculatory function by natural products have been published in international journals.In 2008 and 2017,the first listed author of this review was invited to publish reviews in the journal of Pharmacology&Therapeutics on the improvement of microcirculatory disturbances and organ injury induced by I/R using Salvia miltiorrhiza ingredients and other natural components of compounded Chinese medicine,respectively.This review systematically summarizes the effects,targets of action,and mechanisms of natural products regarding improving I/R-and LPSinduced microcirculatory disturbances and tissue injury.Based on this summary,scientific proposals are suggested for the discovery of new drugs to improve microcirculatory disturbances in disease.

Foeniculum vulgare Mill.inhibits lipopolysaccharide-induced microglia activation and ameliorates neuroinflammation-mediated behavioral deficits in mice

Objective:To investigate the effect of Foeniculum vulgare extract against lipopolysaccharide(LPS)-induced microglial activation in vitro as well as cognitive behavioral deficits in mice.Methods:LPS-activated BV-2 cell viability was measured using MTT assay and reactive oxygen species(ROS)was studied using DCF-DA assay.The antioxidative enzymes and pro-inflammatory mediators were analyzed using respective ELISA kits and Western blotting.For in vivo testing,LPS(1 mg/kg,i.p.)was given daily for five days in male Swiss albino mice to produce chronic neuroinflammation.Cognitive and behavioral tests were performed using open-field,passive avoidance,and rotarod experiments in LPS-induced mice.Results:Foeniculum vulgare extract(25,50 and 100μg/mL)significantly attenuated the LPS-activated increase in nitric oxide(NO),ROS,cyclooxygenase-2,inducible NO synthase,IL-6,and TNF-alpha(P<0.05).Moreover,LPS-induced oxidative stress and reduced antioxidative enzyme levels were significantly improved by Foeniculum vulgare extract(P<0.05).The extract also regulated the NF-κB/MAPK signaling in BV-2 cells.In an in vivo study,Foeniculum vulgare extract(50,100,and 200 mg/kg)markedly mitigated the LPS-induced cognitive and locomotor impairments in mice.The fingerprinting analysis showed distinctive peaks with rutin,kaempferol-3-O-glucoside,and anethole as identifiable compounds.Conclusions:Foeniculum vulgare extract can ameliorate LPS-stimulated neuroinflammatory responses in BV-2 microglial cells and improve cognitive and locomotor performance in LPS-administered mice.

Antidepressant effects of Peiyuan Jieyu formula in a mouse model of chronic stress in conjunction with lipopolysaccharide-induced depression

Objective:To explore the mechanism of the Peiyuan Jieyu formula in treating depression by assessing its impact on a lipopolysaccharide-induced(LPS-induced)depression mouse model.Methods:We created a mouse model of depression by exposing mice that had previously received chronic stress to intraperitoneal LPS injections.The mice were divided into the following groups:control,model,fluoxetine,Tiansi Yin,Sini powder,and low-,medium-,and high-dose Peiyuan Jieyu formula groups.Forced swim and tail suspension tests were used to assess the efficacy of the depression(despair)model,and weight gain rates were also measured.Furthermore,serum levels of various depression and inflammation-associated molecules,including tumor necrosis factor-a(TNF-a),interferon-γ(IFN-γ),tryptophan,5-hydroxytryptamine,kynurenine(KYN),and kynurenic acid(KA)were assessed.Furthermore,the expression levels of ionic calcium-binding adaptor molecule-1(IBA-1)and indoleamine 2,3-dioxygenase(IDO)mRNA in hippocampal microglia were measured.Results:The model group displayed greater despair-associated immobility,which was shortened in response to various doses of Peiyuan Jieyu formula.Furthermore,formula administration significantly reduced serum TNF-a levels and hippocampal IDO mRNA expression.The high formula dose also reduced IFN-γand IBA-1 levels,the latter was also decreased in response to the medium formula dose.However,the low formula dose reduced serum KYN level and KYN/tryptophan(TRP)and KYN/KA ratios.Conclusion:The Peiyuan Jieyu formula holds immense potential in treating depression in a mouse model,potentially inhibiting inflammation and improving TRP-KYN metabolic disorders.

Predictive effect of lipopolysaccharide-stimulated inflammatory cytokines on symptoms of generalized anxiety disorder

BACKGROUND Generalized anxiety disorder(GAD)is a relatively common mental disorder.Recently,inflammation,an important factor for the development of depression,has attracted increasing attention.Several studies have shown that inflammatory cytokines can affect the pathophysiological processes of several nervous system diseases.We hypothesized that there is a correlation between the levels of lipopolysaccharide(LPS)-stimulated inflammatory cytokines and the clinical symptoms of GAD.AIM To investigate the predictive effect of LPS-stimulated inflammatory cytokines on symptoms of GAD.METHODS This was a cross-sectional study in which 89 patients with GAD diagnosed at The First Hospital of Hebei Medical University from January 2022 to December 2022 and 70 individuals without anxiety and depression(controls)during the same period were included.Fasting venous blood was collected from all the subjects in heparin tubes,and another 3 ml of blood was supplemented with LPS(10 ng/ml).The plasma levels of 12 cytokines[Interleukin(IL)-1β,IL-2,IL-4,IL-5,IL-6,IL-8,IL-10,tumor necrosis factor(TNF)-α,interferon(IFN)-γ,IL-17A,IL-12p70,and IFN-α]were detected.RESULTS Post-LPS stimulation,the levels of IL-1β,IL-6,IL-8,IL-10,and TNF-αin both the control and GAD groups were significantly elevated above those in the nonstimulated groups,with IL-6 and IL-8 showing marked increases.Increases in IL-8 and TNF-αwere statistically significant in the GAD group(P<0.05).IL-1β,IL-6,IL-8,IL-10,and TNF-αwere found to be significantly correlated with Hamilton Anxiety Rating Scale(HAMA)scores(P<0.05).A negative correlation was observed between IL-10 levels and HAMA scores.Further analysis revealed that TNF-αwas associated with mental anxiety,whereas IL-1β,IL-8,and IL-10 were associated with physical anxiety symptoms,with IL-10 showing a negative correlation with physical anxiety.IL-6 was associated with both mental and physical aspects of anxiety.CONCLUSION The physical symptoms of GAD are related to inflammatory factors.IL-1β,IL-8,IL-10,and TNF-a can be used as predictors of physical or mental anxiety in patients with GAD.

Yeast hydrolysate attenuates lipopolysaccharide-induced inflammatory responses and intestinal barrier damage in weaned piglets

Background Intestinal inflammation is the main risk factor causing intestinal barrier dysfunction and lipopolysaccharide(LPS)can trigger inflammatory responses in various eukaryotic species.Yeast hydrolysate(YH)possesses multibiological effects and is received remarkable attention as a functional ingredient for improving growth performance and promoting health in animals.However,there is still inconclusive on the protective effects of dietary YH supplementation on intestinal barrier of piglets.This study was conducted to investigate the attenuate effects of YH supplementation on inflammatory responses and intestinal barrier injury in piglets challenged with LPS.Methods Twenty-four piglets(with an average body weight of 7.42±0.34 kg)weaned at 21 days of age were randomly assigned to one of two dietary treatments(12 replications with one pig per pen):a basal diet or a basal diet containing YH(5 g/kg).On the 22nd d,6 piglets in each treatment were intraperitoneally injected with LPS at 150μg/kg BW,and the others were injected with the same amount of sterile normal saline.Four hours later,blood samples of each piglet were collected and then piglets were euthanized.Results Dietary YH supplementation increased average daily feed intake and average daily gain(P<0.01),decreased the ratio of feed intake to gain of piglets(P sponse,evidenced by the increase o=0.048).Lipopolysaccharide(LPS)injection induced systemic inflammatory ref serum concentrations of haptoglobin(HP),adrenocorticotropic hormone(ACTH),cortisol,and interleukin-1β(IL-1β).Furthermore,LPS challenge resulted in inflammatory intestinal damage,by up-regulation of the protein or mRNA abundances of tumor necrosis factor-α(TNF-α),IL-1β,toll-like receptors 4(TLR4)and phosphor-nuclear factor-κB-p65(p-NFκB-p65)(P<0.01),and down-regulation of the jejunal villus height,the protein and mRNA abundances of zonula occludens-1(ZO-1)and occludin(OCC;P<0.05)in jejunal mucosa.Dietary YH supplementation decreased the impaired effects of ACTH,cortisol,HP,IL-1βand diamine oxidase in serum(P<0.05).Moreover,YH supplementation also up-regulated the jejunal villus height,protein and mRNA abundances of ZO-1 and OCC(P<0.05),down-regulated the mRNA expressions of TNF-αand IL-1βand the protein abundances of TNF-α,IL-1β,TLR4 and p-NFκB-p65 in jejunal mucosa in LPS-challenged pigs(P<0.01).Conclusion Yeast hydrolysate could attenuate inflammatory response and intestinal barrier injury in weaned piglets challenged with LPS,which was associated with the inhibition of TLR4/NF-κB signaling pathway activation.

Effect of dual targeting procyanidins nanoparticles on metabolomics of lipopolysaccharide-stimulated inflammatory macrophages

Inflammation plays an important role in the occurrence and development of many inflammatory diseases.The purpose of this study was to evaluate the anti-inflammatory effect and metabolic behavior of the dual targeting procyanidins(PC)nanoparticles on lipopolysaccharide(LPS)-stimulated inflammatory macrophages by metabolomics method.The double-targeting PC nanoparticles could specifi cally target both the CD44 receptor and mitochondria,while the single targeting PC-loaded nanoparticles that could target the CD44 receptor on the surface of macrophages.The double-targeting PC nanoparticles had better inhibitory effect than single-targeting PC nanoparticles on the leakage of lactate dehydrogenase and reactive oxygen species overexpression induced by LPS.Amino acid metabolism,energy metabolism and purine metabolism were disordered in LPS-treated group,and metabolic pathway analysis indicated that the double-targeting PC nanoparticles reversed some of LPS impacts.The changes of these potential biomarkers and their corresponding pathways are helpful to further understand the mechanism of PC nanoparticles in alleviating inflammation,and promote their application in nutrition intervention.

Lipopolysaccharide-induced Trigeminal Ganglion Nerve Fiber Damage is Associated with Autophagy Inhibition

Objective This study aimed to determine whether lipopolysaccharide(LPS)induces the loss of corneal nerve fibers in cultured trigeminal ganglion(TG)cells,and the underlying mechanism of LPS-induced TG neurite damage.Methods TG neurons were isolated from C57BL/6 mice,and the cell viability and purity were maintained for up to 7 days.Then,they were treated with LPS(1µg/mL)or the autophagy regulator(autophibib and rapamycin)alone or in combination for 48 h,and the length of neurites in TG cells was examined by the immunofluorescence staining of the neuron-specific proteinβ3-tubulin.Afterwards,the molecular mechanisms by which LPS induces TG neuron damage were explored.Results The immunofluorescence staining revealed that the average length of neurites in TG cells significantly decreased after LPS treatment.Importantly,LPS induced the impairment of autophagic flux in TG cells,which was evidenced by the increase in the accumulation of LC3 and p62 proteins.The pharmacological inhibition of autophagy by autophinib dramatically reduced the length of TG neurites.However,the rapamycin-induced activation of autophagy significantly lessened the effect of LPS on the degeneration of TG neurites.Conclusion LPS-induced autophagy inhibition contributes to the loss of TG neurites.

川藏香茶菜庚素的体外抗炎作用与分子机制研究

为探究川藏香茶菜庚素(Pseurata H)对巨噬细胞炎症模型的抗炎作用及分子机制,利用LPS刺激RAW264.7细胞建立体外炎症模型,并分别以浓度为10、20和40μmol/L的Pseurata H干预该细胞模型。利用CCK-8法检测Pseurata H对细胞增殖活性的影响;Griess法和ELISA试剂盒分别检测细胞上清液中NO、IL-6和TNF-α的含量;Western Blot检测COX-2、iNOS蛋白、p-NF-κB和p-ERK蛋白的表达变化;以RT-qPCR法检测药物干预前后细胞中iNOS、TNF-α、IL-6和IL-1β的mRNA基因表达变化。结果表明:浓度为10、20和40μmol/L的Pseurata H对细胞没有毒性,不同浓度的Pseurata H对LPS诱导RAW264.7细胞炎症模型中NO、IL-6和TNF-α分泌具有很好的下调作用,对iNOS、COX-2、NF-κB、p-NF-κB、ERK和p-ERK蛋白的表达具有良好的抑制作用,且具有浓度效应。Pseurata H具有明显的抗炎作用,其作用机制可能是通过抑制NF-κB/MAPK信号通路而发挥抗炎作用。

巨噬细胞极化为M1型或M2型对铁代谢的影响

目的探讨巨噬细胞极化形成M1型或M2型对铁代谢的影响。方法应用脂多糖(LPS)20 ng/mL或IL-410 ng/mL诱导RAW264.7巨噬细胞极化,电子显微镜下观察处理后的巨噬细胞极化形态特征,采用免疫荧光染色法及Western blot法检测M1型标志物TNF-α和一氧化氮合酶(iNOS)及M2型标志物精氨酸酶1(Arg-1)的表达情况;LPS或IL-4处理后的巨噬细胞与红细胞及铁剂共培养,通过瑞氏染色和铁染色,评价其铁摄入功能;ELISA法检测LPS或IL-4处理后巨噬细胞内及培养液中铁蛋白含量,以评价其铁储存功能。结果LPS处理后巨噬细胞由圆形向多形性转化;同时,TNF-α和iNOS的表达水平明显增加;可见吞噬红细胞现象,胞质中吞噬的铁颗粒明显增多。IL-4处理后巨噬细胞形态也呈多形性改变,同时Arg-1表达水平增加,但未见吞噬红细胞现象,且胞质内吞噬的铁颗粒较少。此外,LPS处理后巨噬细胞胞内铁蛋白含量较IL-4处理后明显增多。结论LPS与IL-4可诱导巨噬细胞形成不同极化亚型,其铁代谢存在明显差异。LPS处理的M1型巨噬细胞对铁的摄入及储存较IL-4处理的M2亚型巨噬细胞增加,有固铁优势。

MUC2基因沉默对脂多糖干扰Caco-2/HT-29细胞紧密连接蛋白表达的影响

肠道黏膜屏障阻碍病原物质入侵的第一道防线是由黏蛋白-2(MUC2)组成的肠道黏液层,覆盖于上皮细胞表面,由杯状细胞分泌而成。脂多糖(lipopolysaccharides, LPS)可通过损伤肠黏膜从而干扰屏障功能的正常发挥。论文对Caco-2/HT-29(3∶1)共培养模拟肠道上皮细胞,通过沉默黏蛋白-2(siMUC2)分析脂多糖对肠道黏液层屏障及其上皮紧密连接结构的影响。结果显示,与对照组相比,LPS组E-钙黏素(E-cadherin)、闭合蛋白mRNA表达量均明显降低。与LPS组相比,LPS+siMUC2组中连接蛋白(claudin)、连接附着分子(JAMA)、E-cadherin以及桥粒(desmosome) mRNA水平显著降低,细胞连接蛋白mRNA水平的下调可能影响细胞通透性进而导致屏障功能紊乱。说明黏蛋白-2作为黏液层骨架蛋白成分可以保护细胞紧密连接蛋白免受LPS的干扰。LPS可诱导Caco-2/HT-29细胞模型黏蛋白-2表达增多以及E-cadherin、闭合蛋白mRNA表达下调。当黏蛋白-2基因被沉默后,LPS可导致细胞紧密连接蛋白mRNA表达量的显著下降,提示肠道上皮细胞紧密连接的屏障功能可能被破坏。

人参皂苷Rb1减轻脂多糖诱导急性肺损伤的作用研究

目的:探讨人参皂苷Rb1(GsRb1)对脂多糖(LPS)诱导急性肺损伤(ALI)的保护作用及其作用机制。方法:C57BL/6小鼠随机分为对照组、模型组、GsRb1给药组(低、中、高剂量组),气管内给予LPS造模,给药组在造模前3 d分别腹膜腔注射给予不同剂量GsRb1预处理,造模12 h将其麻醉,先采集肺泡灌洗液后再处死取出肺组织,计算肺湿/干比,试剂盒检测灌洗液白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)和肿瘤坏死因子-α(TNF-α)水平以及肺髓过氧化物酶(MPO)活性,Western blot检测肺组织核因子-κB(NF-κB)蛋白的表达。结果:高剂量GsRb1能明显降低肺组织湿/干比(P<0.05);中、高剂量GsRb1能明显降低肺组织MPO活性(P<0.05);高剂量GsRb1明显降低小鼠肺泡灌洗液IL-1β和TNF-α水平(P<0.05);高剂量GsRb1能明显降低肺组织NF-κB p65蛋白的表达(P<0.05)。结论:GsRb1可能通过调控NF-κB通路,减轻炎症反应,抑制LPS诱导的小鼠ALI。

益生菌发酵黄芪对LPS诱导的人正常结肠上皮细胞NCM-460氧化损伤保护作用的机制研究

探究益生菌发酵黄芪(fermented Astragali Radix,F-As)与黄芪(Astragali Radix,As)对脂多糖(lipopolysaccharide,LPS)诱导的肠道细胞NCM-460氧化损伤的保护作用及其分子机制。利用MTT法确定了LPS、As和F-As的工作浓度;分别检测并比较了LPS组、As+LPS组和F-As+LPS组,细胞中氧化应激相关指标、抗氧化相关基因在转录水平和蛋白水平表达的变化。与Con组相比,LPS组的活性氧(reactive oxygen species,ROS)和丙二醛(malondialdehyde,MDA)增加(P<0.01),而细胞的存活率、谷胱甘肽(glutathione,GSH)、超氧化物歧化酶(superoxide dismutase,SOD)、总抗氧化能力(total antioxidant capacity,T-AOC)以及细胞中的抗氧化基因在转录水平和蛋白水平均显著降低(P<0.01);而As+LPS组和F-As+LPS组,细胞中的ROS和MDA水平降低(P<0.01),细胞的存活率GSH、SOD、T-AOC以及抗氧化基因在转录和蛋白水平得到恢复(P<0.01),且与As+LPS组相比,F-As+LPS组恢复得更显著(P<0.05)。研究结果提示,As和F-As均可以通过激活抗氧化基因的表达,清除细胞内过多的ROS和MDA,从而对LPS诱导的细胞氧化损伤起到保护作用,且F-As优于As。

脂多糖生物探针法与传统培养法检测水中嗜肺军团菌的比较

目的比较脂多糖生物探针法和传统培养法(包括ISO 11731-2017法即“ISO法”、GB/T 18204.5-2013法即“国标法”)对水中嗜肺军团菌(Legionella pneumophila)的检测能力。方法分别采用脂多糖生物探针法和传统培养法对58份加标水样(其中50份为实际水样加标用于以上两类方法比对测试,8份为纯水加标用于脂多糖生物探针法的方法学性能测试)和50份实际水样进行检测,确定脂多糖生物探针法的检出限、准确度、精密度、特异性和灵敏度,并比较两类方法对50份实际水样加标前的定性结果和50份实际水样加标前后的定量结果。结果脂多糖生物探针法检出限为1.55 CFU/L,准确度为102.10%~139.29%,精密度为0.14%~1.78%,特异性为95.12%,灵敏度为88.89%。50份实际水样加标前脂多糖生物探针法和国标法两种方法(检出或未检出)的定性结果无统计学差异(P>0.05);50份实际水样加标前后脂多糖生物探针法定量结果的中位数(M)高于ISO法测定结果,差异具有统计学差异(P<0.001),两类方法测定结果存在相关(r=0.981)。脂多糖生物探针法检出限(1.55 CFU/L)低于ISO法的(15.74 CFU/L),检测时间(2 d)短于ISO法(10 d)。结论与传统培养法相比,脂多糖生物探针法耗时短,检测性能更优。

槲皮素对奈瑟球菌感染脑膜炎大鼠脑保护作用的研究

目的:探讨槲皮素(Quercetin,Que)对奈瑟球菌感染脑膜炎大鼠脑组织的保护作用及其机制。方法:将180只SD大鼠随机分为正常对照组,模型组,氨苄青霉素(AMP组,200 mg/kg)组,Que低(50 mg/kg)、中(100 mg/kg)、高(200 mg/kg)剂量组,每组30只。除正常对照组外,其余各组大鼠均采用小延髓池注射奈瑟球菌悬液的方法制备脑膜炎大鼠模型。造模后,各组均每12 h给药1次(AMP皮下注射给药,Que灌胃给药),共给药5次。统计各组大鼠存活率,进行症状评分,伊文思蓝渗透法检测血脑屏障(blood-brain barrier,BBB)通透性,HE染色法行脑组织病理学检查,ELISA法检测血浆脂多糖(lipopolysaccharide,LPS)含量和脑组织肿瘤坏死因子α(tumor necrosis factor-α,TNF-α)、白细胞介素1β(interleukin-1β,IL-1β)、白细胞介素6(interleukin-6,IL-6)含量,生化分析法检测丙二醛(malondialdehyde,MDA)含量和超氧化物歧化酶(superoxide dismutase,SOD)、过氧化氢酶(catalase,CAT)活性,Western blot法检测脑组织p65、IκBα、HMGB1蛋白表达。结果:与模型组比较,AMP组和Que中、高剂量组大鼠存活率显著升高且症状评分、伊文思蓝渗透量降低(P<0.01);脑组织病理学改变明显改善;血浆LPS含量和脑组织TNF-α、IL-1β、IL-6、MDA含量降低,SOD、CAT活性升高(P<0.05或P<0.01);p65、HMGB1相对表达量降低而IκBα相对表达量升高(P<0.01)。与AMP组比较,Que高剂量组大鼠存活率升高,症状评分和伊文思蓝渗透量降低(P<0.05或P<0.01);血浆LPS含量和脑组织TNF-α、MDA含量降低,SOD活性升高(P<0.05或P<0.01);p65、HMGB1表达量显著降低且IκBα相对表达量升高(P<0.05或P<0.01)。结论:Que能够通过降低LPS水平、抑制NF-κB炎症通路、下调HMGB1表达、改善抗氧化酶活性,降低脑组织炎症反应和氧化应激损伤,进而达到保护奈瑟球菌感染脑膜炎大鼠脑组织的作用。

PDLSCs-Exo对炎性环境中牙周膜干细胞增殖能力及活性氧水平的影响

目的探讨牙周膜干细胞(periodontal ligament stem cells,PDLSCs)来源的外泌体(exosome,Exo)对炎性环境中牙周膜干细胞增殖及活性氧水平的影响。方法分离培养牙周膜干细胞,提取牙周膜干细胞来源的外泌体,并将其添加至正常及含有10μg/mL脂多糖(lipopolysaccharide,LPS)的牙周膜干细胞培养基中,实验对象分为PDLSCs组、PDLSCs+LPS组、PDLSCs+Exo组、PDLSCs+LPS+Exo组,检测各组牙周膜干细胞对外泌体的摄取能力、增殖能力、细胞内活性氧水平及炎性因子水平。结果在10μg/m L LPS刺激下,牙周膜干细胞增殖能力下降。组间对比,PDLSCs+LPS组较PDLSCs组、PDLSCs+Exo组、PDLSCs+LPS+Exo组增殖能力显著下降,差异有统计学意义(P<0.05);PDLSCs+LPS+Exo组增殖能力较PDLSCs+Exo组降低,差异有统计学意义(P<0.05);细胞内活性氧及炎性因子对比,PDLSCs+LPS组较其余三组细胞内活性氧水平增高,差异有统计学意义(P<0.05)。结论牙周膜干细胞来源的外泌体能够改善LPS刺激导致的牙周膜干细胞增殖活性降低,降低胞内活性氧及炎性因子水平,并提高牙周膜干细胞的抗氧化能力。

脂多糖处理时间对山羊瘤胃上皮细胞损伤的影响

在山羊瘤胃上皮细胞(GRECs)基础培养基中加入1μg/mL脂多糖(LPS),培养3、6、9 h后,检测细胞活性、抗氧化指标、炎症因子及紧密连接蛋白基因的表达。结果发现:1)LPS处理3 h组GRECs的活性显著低于处理6 h和9 h组的,而处理6 h和9 h组GRECs的活性无显著差异;2)LPS处理3 h组GRECs的谷胱甘肽过氧化物酶(GSH–PX)活性极显著低于处理6 h和9 h组的,但MDA含量的变化则相反,GRECs的SOD和CAT活性随LPS处理时间的延长而显著升高,ROS含量则随LPS处理时间的延长而极显著降低;3)LPS处理3h组GRECs的TNF–ɑ和IL–1β相对表达量极显著高于处理6h和9h组的,IL–1β相对表达量随LPS处理时间的延长而显著降低,各组间IL–6相对表达量无显著差异;4)LPS处理3 h组GRECs的ZO–1分布低,随着处理时间延长ZO–1分布增加,LPS处理3 h的GRECs紧密连接蛋白Claudin–1相对表达量显著高于处理6 h和9 h组的。说明随着LPS处理时间的延长,山羊瘤胃上皮细胞能够通过提高自身抗氧化和抗炎症能力来缓解氧化损伤,进而改善细胞屏障功能。

miR-141-3p靶向调控HMGB1对LPS诱导的A549细胞损伤的影响

目的探讨miR-141-3p通过靶向调控高迁移率族蛋白1(HMGB1)对脂多糖(LPS)诱导的A549细胞损伤的影响。方法以Ⅱ型肺泡上皮细胞来源的A549细胞作为研究对象,将miR-141-3p mimics、mimics NC、HMGB1基因过表达质粒(pcDNA3.1-HMGB1)和空载质粒(Vector)分别或共转染至A549细胞中,再采用10μg/ml LPS处理24 h。细胞计数试剂盒8(CCK-8)检测各组细胞增殖活性;比色法检测各组细胞培养上清液中乳酸脱氢酶(LDH)活性;流式细胞术检测各组细胞凋亡水平;酶联免疫吸附测定法(ELISA)检测各组细胞中白介素(IL)-1β、IL-6和肿瘤坏死因子α(TNF-α)水平;双荧光素酶报告基因实验验证miR-141-3p与HMGB1之间的靶向调控关系。结果LPS干预后,A549细胞增殖活性及细胞中miR-141-3p表达水平降低(P<0.05),细胞凋亡率升高(P<0.05),细胞中IL-1β、IL-6、TNF-α水平及上清液中LDH活性升高(P<0.05)。过表达miR-141-3p可增强LPS处理后的A549细胞增殖活性(P<0.05),降低细胞凋亡率及细胞中IL-1β、IL-6、TNF-α水平和上清液中LDH活性(P<0.05)。然而,HMGB1基因过表达可逆转miR-141-3p对LPS诱导A549细胞损伤的改善作用。双荧光素酶报告基因实验证实,HMGB1是miR-141-3p下游靶基因。结论miR-141-3p可抑制LPS诱导的A549细胞凋亡,降低炎症因子表达水平,改善A549细胞损伤,其作用机制可能与靶向调控HMGB1表达有关。

α-倒捻子素通过NF-κB途径抑制LPS/ATP诱导的小胶质细胞中NLRP3炎症小体的激活

目的探究α-倒捻子素(α-mangostin)在脊髓损伤后小胶质细胞炎症模型中作用及相关机制。方法体外培养小鼠小胶质细胞系BV-2细胞,利用脂多糖和三磷酸腺苷(LPS/ATP)联合诱导的方式建立BV-2炎症模型。CCK-8法检测不同浓度(0、10、20、40、80μmol/L)的α-mangostin对LPS/ATP刺激下的细胞增殖活力影响以筛选适宜的α-mangostin浓度范围;将BV-2细胞分为Ctrl组、LPS/ATP组、40μmol/Lα-mangostin组和不同浓度(10、20、40μmol/L)的α-mangostin干预组(分别记为LPS/ATP+10μmol/Lα-mangostin组、LPS/ATP+20μmol/Lα-mangostin组与LPS/ATP+40μmol/Lα-mangostin组)。ELISA实验检测各组BV-2细胞上清液中促炎因子白介素-6/1β/18(IL-6、IL-1β、IL-18)和肿瘤坏死因子(TNF-α)含量,Western blot检测各组细胞中NOD样受体蛋白3(NLRP3)炎症小体相关蛋白NLRP3、凋亡相关斑点样蛋白(ASC)、裂解型半胱氨酸蛋白酶1(cleaved caspase-1)和白介素1β(IL-1β)表达及核因子κB(NF-κB)途径中p65的磷酸化水平(p-p65/p65)和BV-2细胞核中p65的表达。结果与Ctrl组相比,LPS/ATP组细胞增殖活力明显降低(P<0.05),但低浓度(10、20、40μmol/L)的α-mangostin可显著改善LPS/ATP对小胶质细胞增殖活力的抑制作用(P<0.05),但高浓度(80μmol/L)α-mangostin可促进LPS/ATP对小胶质细胞的损伤(P<0.05)。与Ctrl组相比,40μmol/Lα-mangostin组小胶质细胞上清液中炎症因子IL-6、IL-1β、IL-18、TNF-α含量和细胞中NLRP3、ASC、cleaved caspase-1、IL-1β和p-p65/p65比值及细胞核中p65蛋白均无明显改变(P>0.05),而LPS/ATP组均显著增加(P<0.05);与LPS/ATP组相比,不同浓度α-mangostin干预组中IL-6、IL-1β、IL-18、TNF-α含量和BV-2细胞中NLRP3、ASC、cleaved caspase-1、IL-1β和p-p65/p65比值及细胞核中p65蛋白表达随α-mangostin浓度的增加而依次降低,其中以LPS/ATP+40μmol/Lα-mangostin组的降低程度最为明显(P<0.01)。结论α-mangostin可通过NF-κB途径抑制BV-2细胞中NLRP3炎性小体活化所介导的神经炎症反应。